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Offset-map the entire offset region with 1G pages

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Instead of building nested page tables for the offset region, just
offset map the entire thing into kernel memory with one PDP mapping
1GiB large pages. This is more efficient and avoids the "need a
page table to map in a page table" dependency loop.
This commit is contained in:
Justin C. Miller
2019-03-09 14:52:36 -08:00
parent 2035fffa1c
commit 67b9f45004
3 changed files with 14 additions and 89 deletions
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12
src/kernel/page_manager.cpp
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@@ -143,15 +143,8 @@ page_manager::delete_process_map(page_table *pml4)
void
page_manager::map_offset_pointer(void **pointer, size_t length)
{
uintptr_t *p = reinterpret_cast<uintptr_t *>(pointer);
uintptr_t v = *p + page_offset;
uintptr_t c = ((length - 1) / frame_size) + 1;
log::info(logs::paging, "Mapping offset pointer region at %016lx size 0x%lx", *pointer, length);
page_table *pml4 = get_pml4();
page_in(pml4, *p, v, c, false, true);
*p = v;
*pointer = kutil::offset_pointer(*pointer, page_offset);
}
void
@@ -166,9 +159,8 @@ page_manager::get_table_page()
{
if (!m_page_cache) {
uintptr_t phys = 0;
size_t n = m_frames.allocate(32, &phys);
size_t n = m_frames.allocate(32, &phys); // TODO: indicate frames must be offset-mappable
uintptr_t virt = phys + page_offset;
page_in(get_pml4(), phys, virt, n);
m_page_cache = reinterpret_cast<free_page_header *>(virt);